This is sort of a known issue for all non-turbo 2019-2022 model years for Mazda3 (talking here about US market).
Mazda doesn’t use a mechanical thermostat but an electronic one called Coolant Control Valve (CCV) and in the issued TSB (that got several revisions) they mentioned the problem is within the CCV with the fail-safe thermostat which seems to be opening too soon (some folks opened the CCV and manually adjusted that fail-safe thermostat and seems that the problem got fixed for them).
Personally I had this CCV replaced twice under warranty and issue wasn’t fixed and ended up being unsure on the root cause with dealers ended up being out of ideas and with open case with Mazda.
What is known now is that turbo engines never used CCV and from MY2023 they moved back to a classic thermostat and seems to have abandoned the CCV idea completely.
This is sort of a known issue for all non-turbo 2019-2022 model years for Mazda3 (talking here about US market).
Mazda doesn’t use a mechanical thermostat but an electronic one called Coolant Control Valve (CCV) and in the issued TSB (that got several revisions) they mentioned the problem is within the CCV with the fail-safe thermostat which seems to be opening too soon (some folks opened the CCV and manually adjusted that fail-safe thermostat and seems that the problem got fixed for them).
Personally I had this CCV replaced twice under warranty and issue wasn’t fixed and ended up being unsure on the root cause with dealers ended up being out of ideas and with open case with Mazda.
What is known now is that turbo engines never used CCV and from MY2023 they moved back to a classic thermostat and seems to have abandoned the CCV idea completely.